Object tracking is an important issue in the field of computer vision, and has wide application scenarios. Through object tracking, a specified object can be tracked in a dynamic or static image sequence such as video images, and the position of the object in each frame or each image in the image sequence can be output. Generally, an object region of rectangle shape or another shape, for example, is used to indicate the position of the object.
In popular object tracking techniques, the size of the output object region is fixed, without changing along with the change in the shape or size of the object. In a few advanced object tracking techniques, the size of the output object region can change, but the shape thereof does not change (that is, the aspect ratio does not change). A very few advanced object tracking techniques relate to a object region of which the shape or the size changes arbitrarily.